Translating device



April 30, 1940.

J. G. FRAYNE TRANSLATING DEVICE 3 Sheets-Sheet 1 Filed May 4, 1937 INVENTOR By J. G. FRAVNE 'AHut ATTORNEY J. G. FRAYNE 2,199,070

TRANSLATING DEVICE Filed May 4, 1937 3 Sheets-Sheet 2 INVENTOR By JGFRAV/VE ATTORNEY ATTORNEY April 30, 1940( J. G. FRAYNE TRANSLATING DEVICE Filed May 4, 1957 3 Sheets-Sheet 3 4 a Q E a 5 m w y W i a w y with respect to a single sound source.

. rality of vibrating Patented Apr. 30, 1940 UTE STATES TRAN SLATING DEVICE John G. Frayne, Pasadena,

Products, Inc.,

Electrical Research Calif assigncr to New York,

N. Y., a corporation of Delaware Application May 4,

1937, Serial No. 140,59

In Great Britain August 6, 1936 8 Claims. (01. lie-100.3)

This invention relates to light valves and more particularly to improvements in the construction and operation of such devices employed in photographic sound recording systems.

It has been found that for certain purposes, advantages may be gained by utilizing various forms of double track sound records. In one of the sound records of this double track type, known as a push-pull sound record, the two half waves of the sound wave are recorded 180 degrees out of phase in the two separate adjacent tracks. Another sound record of the double track type is known as a stereophonic sound record in which the separate adjacent tracks represent the same sound waves as recorded from different positions A further record of this type is known as the split frequency record in which each'track is a record of the sound frequencies within a certain frequency band included in the recorded sound.

For studio recording of variable density double track records by means of light valves of the wellknown type disclosed in United States Patent 1,638,555, August 9, 1927, to E. C. Wente, two light valves are required, which involves the use of separate light sources and separate optical systems to bring the two modulated light beams to a single recording film.

It has been recognized for some time that substantial economy and increased operating efliciency would be made possible if there could be provided a recording system comprising a single light source, a single optical system and a single unit light valve incorporating separate light modulating units in a single magnet structure. It has been found extremely difficult, however, to provide a single unit light valve having two separate light modulating systems vibrating in a single magnet structure and at the same time 1 maintain the requisite operating efliciency and preciseness of adjustment of the various elements oi the vibrating system of the light valve.

It is the object of this invention to provide a single light valve structure incorporating a plusystems adjustably mounted for efiicient operation'in' the magnetic field of the single light valve structure.

A feature of the of novel adjustable supporting means for the separate light valve ribbons and in the novel arrangement of these supporting means with respect to the magnet pole-pieces to permit accurate tension and spacing adjustment of each ribbon with respect to the pole-pieces.

Another. feature of the invention lies in the invention lies in the provision is housed a film driving provision of means fixedly incorporated in the light valve structure to extend into the region of the aperture formed by the light valve ribbons for deflecting modulated light rays to the exterior of the light valve structure for monitoring purposes.

A further feature of the invention lies in the provision of optical means disposed in the paths of the light beams emerging from the pole-piece apertures for transversely aligning the light beams on the recording film and in the provision of a novel support for said optical means which may be removably mounted in operating position in one of the pole-pieces.

In the drawings:

Fig. 1 is a diagram showing the essential elements of a sound film recording optical system using a light valve as the modulating means;

Fig. 2 is a top plan view of the light valve plate on which one pole-piece, ribbons and ribbon supporting means are mounted as a unit therewith;

Fig.3 is a side view of the plate shown in Fig. 2;

Fig. 4 is a bottom plan view of the pole-piece supporting plate showing the plate face oppositethat shown in Fig. 2;

Fig. 5 is an enlarged section taken through line 5.-5 of Fig. 4;

Flg. 6 is a section Fig. 7;

Fig. '7 is a plan view of the pole-pieces and ribbon support mounted on the supporting plate;

Fig. 7A shows the support for a second light valve pole-piece;

Fig. 8 shows details of the removable holder for the aligning prism of the optical system;

Fig. 9 is a schematic showing of the monitoring means of the invention;

Fig. 10 is a plan View, partly in section, of the recording optical system showing the manner in I which the optical deflecting prisms produce transverse alignment of separate recording light beams on the recording film;

Fig. 11 is a side elevation of the optical system shown in Fig. 10; and

Fig. 12 is an enlarged perspective View, partly in section of the ribbon support and pole-piece.

Referring to Fig. 1, the recording system shown therein includes a recording machine I in which drum 2 for driving a photographic film F. Light rays of constant intensity from a light source 3 are projected by means of condensing lens system 4 to focus at a point between pole-pieces 5 and 6 of a light valve 1. The light rays emerging from the light valve 1 are projected by means of an objective lens systaken through line 6--6 of tem 8 to the film F on drum 2. The light valve 1 includes a member 9 of magnetic material surrounded by an electromagnet I!) for creating a magnetic field at the light valve pole-pieces 5 and 6. A rectangular plate I l is removably secured to the main body portion of the light valve 1 by means of machine screws I2 and I3. Binding posts i4, I5 and I6 are secured to plate H and provide means whereby an input circuit or circuits may be connected to the light modulating elements of the light valve 1 through wires l'l (Fig. 4).

Plate H is apertured as at [8 to allow passage of the modulated light rays to the objective lens 8. One pole-piece 6 and supporting means for the light valve ribbons are secured to plate I I adjacent the aperture la in a manner to be described.

A member I9 is secured to plate II by means of machine screws 26 and 2! (Figs. 2 and 5). Member i9 is provided with an aperture 22 extending into the area of aperture l8 in plate H. The pole-piece 5 is divided into two sections (horizontally as seen in Fig. 7) to facilitate assembly and is secured to the member I9 by means of machine screws 24 and 25 (Fig. 7).

The pole-piece 6 is provided with two oifset recording apertures 26 and 21. An aperture 28 in line with recording aperture 26 and aperture 29 in line with recording aperture 21 constitute what will be called monitoring apertures, the purpose of which will be explained further in this specification.

In Figs. 3, 4 and 7A the member 36 constitutes a carrier for the second light valve polepiece 5. This pole-piece 5 is divided into two sections to facilitate assembly and is secured to member 36 by means of machine screws 32 and 33. This member 36 has an aperture 34 in line with offset recording apertures 35 and 36 of pole-piece 5. Monitoring apertures 31 and 38 are provided in pole-piece 5 to be in alignment with monitoring apertures 28 and 29 of polepiece 6, respectively, when the light valve 1 is assembled. While applicant discloses separate recording apertures and monitoring apertures, such as 26 and 28 respectively, a single aperture may be provided of such a length as to include the areas occupied by the two separate apertures. Member 30 has secured thereto, by machine screws 42 and 43, members 40 and 4| (Fig. 5) which are provided with apertures 44 and 45 to allow passage of monitoring light beams to the exterior of the pole-piece structure at right angles to the recording light beam.

The novel means provided for directly monitoring the operation of the vibrating systems of the light valve comprises, in addition to the aligned pole-piece monitoring apertures 28-3'I and 29-58, members 46 and 4'! of light transmitting material, preferably quartz. Each of these members has one end extending into the area of the monitoring apertures 28 and 29, respectively, (Fig. 12). The end extending into the area of the aperture is beveled as at 48 and is provided on this beveled portion with an inner reflecting surface'to deflect light rays coming through the apertures along the members 46 and 41. Each of the rods 46, 4'! is covered throughout its length, except for the area immediately in front of the monitoring aperture, with a protective coating of opaque material 50, which, in this disclosure, is a thin metallic covering. As shown schematically in Fig. 9, the light rays emerging from rods 46 and Marc projected to the exterior of the pole-piece structure and are deflected thereafter by suitable optical prisms 5| and lenses 52 to photosensitive devices 53 connected in a suitable reproducing circuit. This novel monitoring feature may be applied to a single string and to a two string light valve having a single recording aperture by employing one only of the light transmitting rods in the pole-piece structure of the single string or two string light valve.

The constant intensity light beam from light source 3 which passes through aligned recording apertures 35 and 26 in opposed pole-pieces 5 and 6, respectively, is modulated by means of vibrating ribbons 55 and 56, while the constant intensity light beam projected through aligned apertures 36 and 3'! in opposed pole-pieces 5 and 6, respectively, is modulated by means of vibrating ribbons 58 and 59. It will be noted that the four vibrating ribbons 55, 56, 58 and 59 are mounted alternately in separate, but parallel planes.

Referring particularly to Figs. 6, 7 and 12, the novel adjustable means for anchoring the ribbon ends comprises a plurality of supporting members 60, BI, 62, 63, 64, 65, 66 and 61. Fig. l2 shows in detail the manner in which these supports are mounted in member l9. Supports 66, 6|, 64 and 65 employed to support ribbons 58 and 59 are shown in detail in the figure.

Member i9 is provided on each side of the polepiece 5 with internal side flanges 68 and 69. The entire inner surface of member I 9 in contact with the ribbon supporting members is covered with an insulating material 76. As each of the ribbon supporting members is identical and each is supported in the member [9 in identical manner, the description of one supporting member and the manner in which it is mounted in member l9 will suifice.

Referring particularly to Figs. 6 and 12, opposite ends of a rigid bar 1|, composed of some suitable insulating material, engage the under side of flanges 68 and 69. A machine screw 12 extending through member 1| engages a threaded hole in the bottom of member 66. Member 60 rests on flange 68 and on central supporting bar 13 of some suitable insulating material. It is evident from this disclosure that tightening of screw 12 will anchor member 60 rigidly in place in the member l9. Each of the ribbon supports 6| to 61, inclusive, are mounted in the manner described above in connection with support 60 and the supportsare electrically insulated from each other and from the mounting member l9.

As shown particularly in Fig. 7, numerals 15 and I6 designate spacing blocks of solid construction which are rigidly mounted in the member IS in the same manner as the ribbon supports.

In Fig. 12 of the drawings applicant discloses the ribbon supports 60, 6|, 64 and for supporting vibrating ribbons 58 and 59 and also the means provided for spacing and tension adjustment of these ribbons. Supports 62, 63 and 61 for ribbons 55 and 56 are adjustable as to tension and spacing in an identical manner and for the sake of clearance applicant has eliminated the latter supports from the disclosures in Fig. 12.

It will be seen that ribbon support 64 comprises two standards H4 and H5 rising from a common base. Standard I I4 is substantially rigid. The ribbon suspending standard H5 is provided with an aperture 80. The provision of aperture 80 in standard H5 and the fact that the two standards are separated throughout the duces sufficient movement thereof in a direction at right angles to the length of the ribbon 59'to provide the necessary lateral spacing adjustment of this ribbon with respect to the recording aperture 2'! in pole-piece 5 and with respect to -ribard 86 there is sufricient space between member bon 58. Standard 19 of support is'adjustable in the samemanner by means of a machine screw ti. Supports BI and are each adjustablein a manner similar to that described in connection with supports 60 and 64 to provide spacing adjustment for ribbon 58.

Means for adjusting the tension of ribbon 59 is provided at support 60 for this ribbon. Figs. 7 and 12 disclose that the tension of ribbon 59 is adjusted by means of a machine screw 8d threaded through standard 19 of support t0 to bear against'the adjacent rigidly mounted spacing block 15 (Fig. 7). Movement of machine screw 84 against member 15 will produce move- ,ment of standard 19 in the direction of the length of ribbon 55 to produce the necessary tension therein. H v

The tension of ribbon 58 is adjusted by a movement of standard 86, of support iii in the following manner. Standard has secured thereto by means of a machine screw Bl. a rigid member "88 provided at its free end with a machine screw 89 which passes through member 88 and into a threaded hole in standard 85 of support 5|. As standard 85 is wider'than stand;

88 and Standard 85 to' permit movement of the standard toward'or away from this member. Rotation of machine screw 89 in a. clockwise direction produces sufficient movement of 'stand-' ard 86 of support 6! to produce a tension in ribbon 58. The tensioning means for ribbons 55 and 56 are .identical'with those of .59fand 58 respectively and are associated with 'the end ribbon supports 65 and 61 located at the opposite side of pole-piece 6 (Fig. '7).

Ribbon 59 is anchored to standard 19 of support 50 by means of a clamping barlllfl which is provided with two machine screws 5-! extend ing into threaded holes in standard E9. The opposite end of ribbon 53;.is anchored to standard H5 of support 54 by means or" a clamp 92, provided with'mac hine screws 93 extending into threaded holes in standard 5 l5. Ribbons 55, 55 and 58 are anchored to their respective supports by clamps similar to clamps and 92. The width of the ribbon engaging projection of the clamps 90 and 92 is slightly smaller than the width of the'vibrating ribbon clamped thereby to insure against buckling of the vibrating edges of ribbon 59. r v

The vibrating'ribbons 55, 5E, 58 and 59 are supplied with sound modulated electric currents from arecording microphone circuit connected to binding-posts l4 and I5 mounted on plate It Wires I! carry these microphonic currents to electrically conductive pins embedded in a strip of insulating material 95 secured to plate -.I l.

Separate insulated wires such as 95 (Fig. 8} con posite to. the

nect each of these pinsto the separate machine screws 72 associated with each of the-members 64 to 51 inclusive supporting one end of each of ribbons 55, 56. 58 and 59. The supports associated with the'ctherv end of each of ribbons 55, 5B, 58 and 59 are each electrically connected through'an associated machine screw 12 and wire 96 to one of the electrically conductive pins embedded in a strip of secured to plate ll. Ribbons 55 and 55 areelectrically connected to form a loop by means of 59 are connected electrically, as shown schematically in Fig. 9, to produce a push-pull sound rec'- ord. The sound modulated currents are conducted through the pair of conductors 58 and as forming one vibrating system in a direction opdirection of the same currents through the pair of conductors 55 and 55 forming the other vibrating system. It is quite apparent, however, that the'twovibrating systems may be connected. after minor modifications, to separate electrical circuits for production of eitherv stereophonic or split frequency sound records. Also, noise reduction currents may be connected to the vibrating systems in an appropriate manner and in the present disclosure the binding post It is supplied for this purpose. a 4

insulating material 9'1 It canreadily be seen that due to the-offset of a the recording apertures 25 and 2'! in pole-piece 6, the separate modulated light beams willbe projected to and recorded on film F inseparate tracks in offset relation, that is, the two simul-- taneously recorded records will not be in trans verse alignment on the recording film. In practically all sound film reproducing equipment a single transverse slit is employed to limit the area of the reproducing light beam to thefilm sound record. Therefore, double track sound records of any of the types discussed above and wherein the two tracks are displaced relative to each other longitudinally of the film could not be reproduced in standard theatre reproducing 1 apparatus.-

To avoid the necessity of modifying existing sound reproducing apparatus, applicant provides means whereby transverse alignment of the oilset' modulated light beams from. the recording light valve pole-pieces is produced in the recording optical system between the light valve and film.

Referring"particularly to 10 and 11, the m'odulated'lightbeam emerging from aperture 21 in pole-piece 5 is intercepted by light'transmitting and'refracting member lilii sodisposed that the light beam is-deflected downward. The

modulated light rays'emerging'from aperture 26 in pole-piece 6 are intercepted by light transmitting and 'refracting element It! so disposed thatthemodulated light beam is deflected up ward. The angle at whichthese retracting elements are disposed in the-'opticalsyst'em is so chosen that the two beams will be in tram verse alignment at the optical axis of the recordingoptical system and will be recorded on film 36 in transverse alignment side by side.

Referring to Figs, 5 and 8, applicant discloses a novel-holder for the refractor elements I38 and Hill. This holder comprises an element having side walls. Hi2 and tured transverse portions I'M, l05and I06. Refl Hi3 joined by 'aper fractor plates I and .IOI have their ends mounted in the portions I04, I05 and I06 as shown in Fig. 8. These refractors may be adjusted in their mounting and maintained in adjustmentiby the application at the mountings of a small amount of cement or other suitable sealing material. In the event readjustment is necessary at any time, this seal may be easily broken and reformed after readjustment has been made.

The holder may be removably inserted into member I9 with the, refractor elements adjacent the recording apertures in pole-piece 6. The side walls I02, I03 are made slightly flexible in the manner shown and are each provided with a projection I01. Other portions of the side walls are flanged as at I08. The knurled portions of side walls I02 and'I03 may be taken between the thumb and forefinger and sufficient pressure exerted thereon to permit. passage of the holder into aperture 22 in member I0 until flange I08 engages a face of member I9. The holder is held in member I9 by means of the projection I 01, which extends into a recess I09 in the inner side wall of member I9,

It will be noted that one end of each of the ribbons 55 and 59 is supported adjacent the polepiece 6 by supports 63 and 60, respectively. As the amplitude of movement of these ribbons depends both on the strength of the constant magnetic field and the current through the ribbons,

the portion of the ribbon between the pole faces is subject tothe maximum and therefore greater moving force than the end portions of the ribbons not included between the pole faces. It is therefore evident that one end of each of the ribbons 55 and 59 clamped to supports 63 and 64, respectively, are subjected to a greater shearing strain at the point of clamping than the: ribbons clamped by the remaining supports further removed from the pole-pieces.

To reduce the possibility of ribbon shearing at the supports 63 and 64, the strength of magnetic field at certain portions of the pole faces of pole-pieces 5 and 6 is reduced by removing small portions thereof directly adjacent supports 63 and 64 as at H0 and III on polepiece 5 (Fig. 7A) and at H2 and H3 on 01epiece 6 (Fig. 7).

What I claim is:

l. Thecombination in a light valve having oppositely disposed pole-pieces provided with aligned apertures and a pair of conducting elements arranged between said pole-pieces to form a light transmitting slot, of means for monitor ing the movements of said conducting elements, said means comprising a light transmitting element mounted in one of said pole-pieces with one end extending into a portion of the physical area of the aperture therein, and light sensitive means included in a reproducing circuit disposed in the path of light emitted from the opposite end of said element. i

2. The combination in a light valve having oppositely disposed pole-pieces provided with aligned rectangular apertures and a plurality of conducting elements arranged between said polepieces for movement in frontof the apertures therein, of means for monitoring the movements of said conducting elements comprising a light transmitting element mounted in one of said pole-pieces at an angle to the longer axis of the aperture therein with one end thereof extending into a portion of the physical area of the aperture in said pole-piece, the other end of said element extending to the exterior of said polepiece structure.

3. A light valve comprising apair of oppositely disposed pole-pieces each having a pair of light transmitting apertures, a conducting element movable in front of the apertures in said polepieces to vary the amount of light projected therethrough, and means for utilizing the light beam projected through one of said apertures for monitoring purposes.

4. The combination in a light valve having oppositely disposed pole-pieces provided with aligned apertures and a plurality of movable conducting elements disposed between said polepieces, of light transmitting means mounted in one of said pole-pieces, said means having one end thereof beveled and provided with a reflecting surface extending into a portion of the physical area of the aperture in said pole-piece and the other end thereof extending through the exterior of the pole-piece structure whereby a portion of the light beam modulated by said conducting element is made available for monitoring purposes.

5. A sound recording system comprising means to project a beam of light to a record surface and means to modulate said beam in accordance with the sounds to be recorded, said means comprising a light valve having oppositely disposed polepieces provided with a plurality of aligned apertures, a plurality of conducting elements movable between said pole-pieces to vary the amount of light projected through the plurality of apertures therein, means for monitoring the movement of said conducting elements, said means comprising a plurality of light transmitting elements mounted in one of said pole-pieces in non-interfering relation with said conducting elements, each light transmitting element having one endthereof extending into the physical area of certain of said apertures with the other end thereof extending to the outer boundary of the pole-piece structure, and a light sensitive means disposed in the path of light from each of said light transmitting elements. I

6. The combination in a recording optical system having means to project a beam of light to a recording film, of means to modulate, said light beam in accordance with sounds to be recorded, said means comprising a light valve having oppositely disposed pole-pieces each provided with a pair of aligned apertures displaced in opposite directions with respect to the optical axis of the recording system, conducting elements disposed between said pole-pieces and movable in response to sound currents to vary the amount of light passing through each of the aligned apertures in said pole-pieces, and optical means intercepting each of the modulated light beams from said pole-pieces for deflecting each beam toward the optical axis of the recording system whereby the pair of modulated beams will be recorded on said film in transverse alignment.

'7. A light valve comprising a pair of oppositely disposed pole-pieces each having a pair of light transmitting apertures, a conducting element movable in front of the apertures in said polepieces to vary the amount of light projected therethrough, and means mounted'in one of said light valve pole-pieces for deflecting the modulated light beam projected through one of the apertures therein whereby said deflected beam may be utilized for monitoring purposes.

8. The combination in a recording optical system having means to project a beam of light to (iii voptical system sounds to be recorded, and means disposed in said optical system for deflecting the modulated beams projected through the apertures in said member in opposite directions to produce horizontal alignment of said beams in the plane including the optical axis of said system at the 5 recording surface of said film.

, JOHN G; FRAYNE. 

